> For the complete documentation index, see [llms.txt](https://giantgrey.gitbook.io/tileworldcreator-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://giantgrey.gitbook.io/tileworldcreator-documentation/custom-actions.md).

# Custom actions

In TileWorldCreator, an action is either a generator or a modifier. The main difference between a generator and a modifier is, that a generator is basically a function/algorithm which creates a map from scratch, while a modifier modifies an existing map and returns the modified map. You can easily create your own custom actions for TileWorldCreator, read further to see how.

### Template

> Simply use this template code to create your own action. You can also find this class in the TileWorldCreator folder under: `TileWorldCreator / Code / Actions / Modifiers / _MyCustomAction.cs`

```csharp
    using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;
    #if UNITY_EDITOR
    using UnityEditor;
    #endif

    using TWC.editor;

    namespace TWC.Actions
    {
      // Define the category for this action (Generator or Modifier)
      // Modifier
      [ActionCategoryAttribute(Category=ActionCategoryAttribute.CategoryTypes.Modifiers)]
      // Generator
      //[ActionCategoryAttribute(Category=ActionCategoryAttribute.CategoryTypes.Generators)]

      // Set the name of this action
      [ActionNameAttribute(Name="MyCustomAction")]
      // Inherit from TWCBlueprintAction and implement the ITWCAction interface
      public class MyCustomAction : TWCBlueprintAction, ITWCAction
      {

        // Clone function
        // This is called when the user duplicated this action
        // Simply return a new class of this type and assign all parameters
        public ITWCAction Clone()
        {
          var _r = new MyCustomAction();
          return _r;
        }

        // Custom gui layout. If we want to implement a custom gui for this action we need this 
        // guilayout, so that the reorderable list can draw the gui correctly.
        TWCGUILayout guiLayout;

        // The actual execution method which gets called by TileWorldCreator.
        // Here you can make your map modifications. Make sure to return the new map.
        public bool[,] Execute(bool[,] map, TileWorldCreator _twc)
        {
          // Simple example: 
          // Here we are inverting all tiles of the map
              for (int x = 0; x < map.GetLength(0); x ++)
              {
                  for (int y = 0; y < map.GetLength(1); y ++)
                  {
                      map[x,y] = !map[x,y];
                  }
              }

          // return the newly modified map
              return map;
        }

        #if UNITY_EDITOR
        // Custom gui for this action
        public override void DrawGUI(Rect _rect, int _layerIndex, TileWorldCreatorAsset _asset, TileWorldCreator _twc)
	{
          // Use the guiLayout to make sure the gui is drawn correctly in the reorderable list
          using (guiLayout = new TWCGUILayout(_rect))
          {
            // Example: Show a label
            // Before adding a gui element first call guiLayout.Add();
            guiLayout.Add();
            // Use the guilayout.rect for the correct rect
            GUI.Label(guiLayout.rect, "Hello World");
          }
        }
        #endif
        
        // Must be implemented when using a custom gui.
        // Here we're returning the height of the guiLayout.
        public float GetGUIHeight()
        { 
          if (guiLayout != null)
          {
            return guiLayout.height;
          }
          else
          {
            // Return default single line height
            return 18;
          }
        }
      }
    }
```

Make sure the class inherits from `TWCBlueprintAction` and implements the `ITWCAction` interface.\
Then you can add your custom map modification code inside of the `Execute` method and return the modified map.\
All custom GUI code should be inside of the `DrawGUI` method.